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🔊 #NowPlaying on #BBCRadio3:
#ChoralEvensong
- Portsmouth Cathedral
Live from Portsmouth Cathedral, with music by Martin Baker, Stanford, John Rutter and Philip Moore.
Relisten now 👇
https://www.bbc.co.uk/programmes/m002f0kt

At the Max Planck Institute for Solar System Research, we do cutting edge scientific research on our Sun, the planets and their moons, asteroids and comets. Posts will be in English und manchmal auch auf Deutsch.
#mpsgoettingen #introduction

Geometric Duality Between Constraints and Gauge Fields: Mirror Symmetry and Spencer Isomorphisms of Compatible Pairs on Principal Bundles
Dongzhe Zheng
https://arxiv.org/abs/2506.00728

Geometric Duality Between Constraints and Gauge Fields: Mirror Symmetry and Spencer Isomorphisms of Compatible Pairs on Principal Bundles
This paper develops a mirror symmetry theory of Spencer cohomology within the geometric framework of constrained systems on principal bundles, revealing deep symmetric structures in constraint geometry. Based on compatible pairs $(D,λ)$ under strong transversality conditions, we construct a systematic family of mirror transformations: from basic sign mirrors $λ\mapsto -λ$ to general automorphism-induced mirrors $λ\mapsto (dϕ)^*(λ)$. Our core result proves that these transformations preser…

Shame about the appalling ‘fearless motivation’ background music, but if you can get past that, Tim Minchin’s 9 life lessons are goodies.
https://www.facebook.com/share/v/1DX5KtjvPt/?mibextid=wwXIfr

147M views · 363K likes | Tim Minchin - Live To Learn | These 9 life lessons from comedian Tim Minchin will make you laugh -- and learn! Source: The University of Western Australia | By RISE | Facebook
These 9 life lessons from comedian Tim Minchin will make you laugh -- and learn! Source: The University of Western Australia

This https://arxiv.org/abs/2303.17191 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

On the continuity of Følner averages
It is known that if each point $x$ of a dynamical system is generic for some invariant measure $μ_x$, then there is a strong connection between certain ergodic and topological properties of that system. In particular, if the acting group is abelian and the map $x\mapsto μ_x$ is continuous, then every orbit closure is uniquely ergodic. In this note, we show that if the acting group is not abelian, orbit closures may well support more than one ergodic measure even if $x\mapsto μ_x$ is contin…

Getting almost all the bits from a quantum random access code
Han-Hsuan Lin (National Tsing Hua University, Taiwan), Ronald de Wolf (QuSoft, CWI,University of Amsterdam)
https://arxiv.org/abs/2506.01903

Getting almost all the bits from a quantum random access code
A quantum random access code (QRAC) is a map $x\mapstoρ_x$ that encodes $n$-bit strings $x$ into $m$-qubit quantum states $ρ_x$, in a way that allows us to recover any one bit of $x$ with success probability $\geq p$. The measurement on $ρ_x$ that is used to recover, say, $x_1$ may destroy all the information about the other bits; this is in fact what happens in the well-known QRAC that encodes $n=2$ bits into $m=1$ qubits. Does this generalize to large $n$, i.e., could there exist QRACs tha…

Computability of a Whitney Extension
Andrea Brun, Guido Gherardi, Alberto Marcone
https://arxiv.org/abs/2507.02113 https://arxiv.org/…

Computability of a Whitney Extension
We prove the computability of a version of Whitney Extension, when the input is suitably represented. More specifically, if $F \subseteq \mathbb{R}^n$ is a closed set represented so that the distance function $x \mapsto d(x,F)$ can be computed, and $(f^{(\bar{k})})_{|\bar{k}| \le m}$ is a Whitney jet of order $m$ on $F$, then we can compute $g \in C^{m}(\mathbb{R}^n)$ such that $g$ and its partial derivatives coincide on $F$ with the corresponding functions of $(f^{(\bar{k})})_{|…

Unpack AI’s environmental impact today at 11am EDT, from local vs global effects to how it stacks up against Netflix flights. Try out a new student-friendly tool brainstorm classroom ideas in this #MyFest25 webinar HT @…

Face to face with solar telescopes, meteorites and exoplanets: For the 6th Night of Science on June 21st 2025 in Göttingen, the MPI for Solar System Research is offering a full program of hands-on activities, lectures, guided tours, and unique exhibits.
Infos by MPS: https://www.mps.mpg.de/night-of-science-20

One-Parametric Presburger Arithmetic has Quantifier Elimination
Alessio Mansutti, Mikhail R. Starchak
https://arxiv.org/abs/2506.23730 https://

One-Parametric Presburger Arithmetic has Quantifier Elimination
We give a quantifier elimination procedure for one-parametric Presburger arithmetic, the extension of Presburger arithmetic with the function $x \mapsto t \cdot x$, where $t$ is a fixed free variable ranging over the integers. This resolves an open problem proposed in [Bogart et al., Discrete Analysis, 2017]. As conjectured in [Goodrick, Arch. Math. Logic, 2018], quantifier elimination is obtained for the extended structure featuring all integer division functions $x \mapsto \lfloor{\frac{x}{f(…